High above the Piazza del Popolo is a green area – where you can go and relax between shaded trees if you want to get away from the famous buildings and the crowd in the center of Rome. The entrance to this area is the Pincio from where you have a great view out over the central part of Rome from the top of the hill.
You can see the view of Rome from a platform at the top – the platform was under repair when I went but it was still possible to get close enough to the edge to actually enjoy the view.
The platform is in front of the area around Piazza Napoleon around this square is a lot of statues of famous Italians. Unfortunately my knowledge of Italian politics isn’t sufficient to know who the different people are. From the square you can go on to the park around Villa Borgehese.